By Sam Kim SEOUL, June 22 (Yonhap) -- South Korea said Monday it has completed the development of a torpedo-tipped guided missile to beef up its naval defense against North Korea.

The "Korean Anti-Submarine Missile," or KASM, will be deployed on the country's most advanced destroyers starting next year after mass production, the state-run Agency for Defense Development (ADD) said.

The KASM, which can travel about 20 kilometers in the air, carries a lightweight torpedo that is unleashed into the water to find and destroy a target, ADD officials said.

Similar to the U.S.-made Vertical Launch Anti-Submarine Rocket, or VLA, the Korean-made rocket comes after nine years of development that cost nearly US$80 million, Bae Yeon-sook, an ADD developer, said in a briefing.

A 2004-built torpedo dubbed "Blue Shark" is loaded into the missile and parachuted into the water to minimize impact, ADD noted.

"The missile can effectively evade enemy detection because it hits its underwater target after flying over the water," Bae said.

Each missile, nicknamed "Red Shark," will cost approximately US$1.5 million, he said. KDX-II and KDX-III destroyers, including the Aegis-guided Sejong the Great, will be capable of carrying the weapon.

"With the development, South Korea's anti-submarine attack capabilities should be upgraded to world class levels," Bae said.

North Korea surpasses South Korea in the number of submarines by a large margin, operating about 70, according to the defense ministry in Seoul.

The two countries remain technically at war after the 1950-53 Korean War ended in a truce. North Korea has recently threatened an armed conflict around the two countries' western sea border where skirmishes turned deadly in 1999 and 2002.